Electric burglar-alarm.



PATENTBD JULY 28, 1903.

S. SGHWARZSGHILD.

ELECTRIC BURGLAR ALARM.

APPLIUATION FILED FEB. 20, 1902,

H0 MODEL.

avwemtoz S Schwarmc/zild.

Patented July 28, 1903 PATENT OFFICE.

SOLOMON SOHWARZSOHILD, OF ROCHESTER, NEW YORK.

ELECTRIC BURG LAR*-ALARM.

SPECIFICATION forming part of Letters Patent No. 734,967, dated July 28 1903;

Application filed February 20, 1902. Serial No. 94,983. (No model.)

CHILD, a citizen of the United States, residingat Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Electric Burglar- Alarms; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable'others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in electric burglar-alarrns, and has for its principal object the utilization of a telephone-circuit for the transmission of an alarm-signal, particularly upon an unauthorized entrance or attempted entrance of a building or premises,to the central telephone-exchange or other point where the call will be responded to.

The present invention was originally shown and described in the United States patent application for improvements in electric burglar-alarms filed by me September 3, 1901, Serial No. 74,171, and has special reference to that form of the invention in which the alarm-signal is sent over the line by means independent of the device employed by the subscriber in sending a call into the central exchange.

vTo this end my said invention comprises the combination and arrangement of parts hereinafter more fully described, and pointed out in the claims.

Referring to the accompanying drawings, Figure 1 is a diagram representing a subscribers telephone-outfit with the apparatus comprising my invention connected to the main telephone-circuit thereof. Fig. 2 is a diagram showing an electromagnetically-operated switch for short-circuiting the line binding-posts of a subscribers telephone instrument, and Fig. 3 is an enlarged sectional detail view of the alarm-clock switch.

Similar letters and numerals refer to similar parts throughout the several views.

A represents a subscribers telephone outfit or instrument-such, for example, as that employed by the Bell Telephone Companywith metallic circuits and central-energy exchanges. I do not, however, confine my invention to Bell telephone-circuits The wires 1 2 represent the subscribers metallic line connected to the binding-posts a and er of the subscribers instrument.

B represents an electromagnetic switch for closing the subscribers line-circuit and sending in the alarm-signal. This switch comprises, among other parts, a blade 5, pivoted, as at b, in a suitable frame b and having a lip 6 adapted to be engaged by a latch b and held in the open position by said latch against the tension of a spring 6 The latch b carries the armature b of an electromagnet 19 The switch-blade when released by the said latch is adapted to engage the switch-point b The blade and point of the switch are connected, respectively, by the wires 3 4 to any convenient points inthe main telephonecircuit, the switch proper beingpreferably inclosed in a suitable casing b which may be located at any desired point. The magnetcoil terminals of the switch B are connected to wires 5 and 6 of a local alarm-circuit. In this circuit I locate any desired number of switches of any desired kind adapted to close the local circuit upon the unauthorized entrance or attempted entrance into the building orpremises to beguarded. Theseswitches may be composed of two normally separated metal plates, such as c and c of the switch O, arranged in any way so as to be normally separated and brought together by said unauthorized entrance or attempted entrance of the guarded building or premises. For ex ample, one of the contacts, as 0, may be countersunk in a door-jamb and the contact 0 on the door proper, so that when the door is closed the electrical connection between the two contacts is broken and when the door is opened connection between the two will be made, or they may be mounted, respectively, upon the casing and sash of a window or under the threshold of a door, or, in fact, in any place where the unauthorized entrance or attempted entrance above referred to will cause said switch to close the local alarm-circuit. This local circuit includes a battery F and, preferably, though not necessarily, a timeswitch D and, if desired, an alarm-clockbperated switch G. The switch D is shown and described in detail in the copending application, Serial No. 74,171, above referred to, and comprises, among other parts, the pivoted arm 'or blade (1, which when released by removing a stop d is driven in a prearranged time into engagement with a contact d by a clock-train (1 thus completing the local circuit from one of its binding-posts to the other. The function of this switch D is to keep the local circuit open long enough to allow the person leaving the building to open the door and get out,when the said switch automatically closes the local circuit. If some device did not keep the local circuit broken when the person leaving opens the door, and thus closes the doorswitch, the alarmsignal would be sent in when there really was no unauthorized entrance.

In order to obviate the necessity of an authorized person entering the building or premises having to answer the call sent by the alarm apparatus, and thereby informing central that the call was not a burglar-alarm, I provide a second switch connected in the 10- cal circuit and 'set to disrupt the said circuit, and thereby render the alarm inoperative at a predetermined time. This may be accomplished in a variety of ways; but the one herein shown consists of a time-switch G, operated by an ordinary alarm-clock H. The switch G consists simply of a resilient-metal contact-piece g, pivotally mounted at one end upon an insulating-block g, secured to the back of the clock and adapted when the switch is closed to rest at its free end upon the top of the alarm-winding nut 9 For the purpose of disrupting the circuit through the switch or, in other words, opening the switch at a predetermined time the winding-nut is provided with an insulating-pin g which upon rotation is adapted to engage a pin g upon the contactspring g, and thus send the latter out of engagement with the windingnut, which opens the switch. This switch may be connected in the circuit in any convenient wayas, for example, by connecting one conductor of the local circuit to the pivotal screw of the spring 9 and the other conductor of the local circuit to any metallic portion of the clock.

The operation of the system is as follows: If the time-switch D is employed, the person last in the room, building, or premises equipped with the alarm before leaving removes the stop d from the switch D. This allows the clock-train thereof to start the blade on its travel toward the contact d The person then opens the door provided with switch C and makes his exit, closing the door after him. In opening the door he closes the switch 0; but the time-switch D is so regulated as to give the person ample time to get out and close the door again (which opens switch 0) before the switch D closes. When the alarm is setthat is, placed in condition to operatethe blade of the switch B is held in the down position shown in fulllines, the switches D and O are closed, and the switch 0 open. Upon the opening of the door provided with the switch 0 or upon any unauthorized entrance this switch, or others of an equivalent character, close the local alarm-circuit through the coils of magnet of the switch B. This done, the said magnet will attract its armature, causing the latch b to release the switch-blade, which will be sent by the spring b into engagement with the contact b This will complete the main telephone-circuit just as it is completed by the hook-switch and will therefore send into the central exchange, if the main circuit leads to a central exchange, a call. The operator at central will answer the call according to the usual practice, but upon receiving no reply will at once notify police headquarters or other proper persons and instruct them to investigate the premises from which the call came. Obviously if the device is located in a large building having a subexchauge or isolated exchange the call would be sent there. I do not, therefore, make use of any of the operating parts, such as the hookswitch or magnets of the subscribers instrument which are used for sending the ordinary call, but employ means entirely independent of the regular subscribers calling apparatus. If the system is placed in a store, for example, and it is desired to render it inoperative just before the usual hour for opening or any other time, the alarm-clock is set to go off at the selected hour. When this takes place, the pin g will rotate and break the connection between the spring-contact g and alarm-winding nut 9 which disrupts the local circuit. This, as before pointed out, prevents the sending of an alarm-call when an authorized person enters.

Obviously I may omit either or both of the time-switches without departing from the principle of my invention.

By the arrangement of the system shown in Fig. 1 it will be seen that the telephone-wires are tapped, as by conductors 3 and 4. In order to avoid the necessity of tapping the main telephone-wires, I have devised the ICO IIO

switch B, which may take the place of the 7 switch B. The switch B consists of magnets b the coils of which are connected in the local alarm-circuit 5 6, as in the case of the apparatus shown, and a pivotal arm I), which carries at one end a pivoted yoke (Z spanning the line-terminal binding-posts usually located at the top of a subscribers instrument. When the magnets b are onergized upon the operation of the system, they attract the arm Z2 into engagement with the binding-posts a and a, thus shortcircuiting the line without tapping the wires. This device forms a very important part of my invention, since it is often undesirable to tap the line-wires of a subscribers instrument.

Having thus described my said invention,

it is obvious that I may make changes and alterations therein without departing from the spirit thereof; but

What I claim, and desire to secure by Letters Patent of the United States, is

1. In an electric burglar-alarm, the combination with a telephone-circuit and a subscribers telephone instrument connected therein, a local alarm-circuit, and an electromagnetic switch operated by said local circuit to send an alarm-signal over said telephone-circuit, said switch comprising a pivoted arm, an electromagnet operated by the local circuit and operating said arm, and a yoke carried by said arm, adapted to shortcircuit the line binding-posts ofsaid subscribers instrument.

2. In an electric burglar-alarm, the combination with a telephone -circuit, of a local house alarm-circuit, electromagnetically-operated means located in said circuit for closing the telephone-circuit, alarm-operating switches located in said local circuit, and an auxiliary timeswitch located in said local circuit adapted to close the said circuit therethrough after the circuit through the alarmoperating switches is open, and a second timeswitch located in said circuit and adapted to break the said circuit at a predetermined time.

3. In an electric burglar-alarm, the combination with a telephone-circuit and a subscribers telephone instrument connected therein, a local alarm-circuit, and an electromagnetic switch operated by said local circuit, said switch being provided with a contact-maker adapted to short-circuit the line binding-posts of said subscribers instrument when the said switch is operated, and to thereby send an alarm-signal over said telephone-circuit.

4. In an electric burglar-alarm, the combination with a telephone-circuit and a subscribers telephone instrument connected therein, a local alarm-circuit, and an electromagnetic switch operated by said local circuit to send an alarm-signal over said teleshort-circuit the line binding-posts of said subscribers instrument.

5. In an electric alarm system of the character described, the combination with a telephone-line leading from a premises to be protected into a telephone-exchange, a local circuit located upon said premises and connected to the main telephone-circuit, electromagnetically-operated means for closing said telephone-circuit through said local circuit, and adapted to send a signal into the said exchange independent of local sounds, a local alarm-circuit for operating said electromagnetic means,alarm-operating switches located in said local alarm-circuit, and an auxiliary time-switch also located in said local alarmcircuit and adapted to close the said alarmcircuit therethrough after the said circuit through the alarm-operating switches is open.

6. In an electric burglar-alarm, the combination with a telephone-circuit and a subscribers itelephone instrument connected therein, a local alarm-circuit, and an electromagnetic switch operated by said local circuit to send an alarm-signal over said telephone-circuit, said switch comprising a pivoted arm, an electromagnet operated by the local circuit and operating said arm, and a contact-piece carried by said arm, adapted to short-circuit the line leading to said subscribers instrument.

In testimony whereof I afiix my signature in presence of two witnesses.

SOLOMON SOHWARZSOHILD.

Witnesses:

W. W. WEBB, A. W. ST. JOHN. 

